NIH-SBIR 94 topic 85, from the National Institute of General Medical Sciences (NIGMS) calls for the development of a new detector for applications in molecular biology and genomics. Development of more sensitive assays, miniaturized formats and multiplexing capabilities are the goals of this application for specific adaptation to the demands of DNA diagnostics. This application address a few outstanding problems which will demonstrate that the proposed instruments are applicable in clinical practice. Specifically, we propose to develop an ultra-sensitive method for detecting biomedically important macromolecules. This new detection technique can be used to quantitate sub-zeptomole (< 10[-21] M) quantities of large molecules such as the fragments of DNA, RNA and large proteins. In the future this technique may be used to develop super-sensitive diagnostic tests using both immunotechniques, e.g. immuno-PCR, and DNA probes. Applications in the detection of a plurality of important diseases are expected. PROPOSED COMMERCIAL APPLICATION: MPD instrumentation is expected to have significant applications in the areas of immunoassays and DNA probes. MPD- assay will, we believe, largely supplant current RIA techniques and will expand the market for high sensitivity and precise quantification immunoassays in general. This market segment is currently in excess of $200 million/year. Furthermore, MPD applications in DNA analysis may account for a few percent of a market expected to exceed $5 billion/year by 1999.